Prickly pear is a flavorful, sweet, and succulent exotic fruit appreciated by national and international consumers. Mexico is the largest producer of prickly pear worldwide; however, a lot of fresh fruit is lost after harvesting due to inadequate storage practices.The major deterioration factors are microbial growth, darkening of peel, and dehydration; all of which depend on storage conditions.Scientists at Universidad de las Américas Puebla (Mexico) have evaluated the effect of some MAP and temperature conditions on the physicochemical, microbiological, antioxidant, and sensory characteristics of prickly pear Villanueva variety.
Villanueva variety, is a white pulp prickly pear grown in San Sebastián Villanueva, Puebla, Mexico. It has an average weight of 100 g and an amount of pulp and skin of 51.6 and 47.4%, respectively. The total soluble solids (13.5%), pH (5.37), and titratable acidity (0.07% as citric acid) are similar to those physicochemical characteristics in other white prickly pears varieties.
For the study, unpacked prickly pears (WOP, control) and packaged under passive (PA, .3 ±0.1% O2 and 0.03±0.0% CO2) and active (AA, 6.25±0.1% O2 and 3.65±0.1% CO2) atmospheres were stored at 4°C, 10°C, or 27°C. Fruit were evaluated for weight loss, color, firmness (=evaluated on peeled and unpeeled fruit), bioactive compounds, microbial load, and sensory characteristics every 10 days for 40 days. Prickly pears (unpeeled and peeled) were sensory evaluated using a hedonic scale of seven points, where number 7 means "Like very much" and number 1 means "Dislike very much." Fruit were evaluated at 0, 10, and 20 d using twenty untrained judges. Judges were growers and consumers of prickly pears. Color, aroma, texture, flavor, and overall acceptability were evaluated.
Results showed that the storage of prickly pears in passive or active atmosphere delayed weight loss, dehydration, and changes in external color that were decisive to the acceptance of the products. The storage conditions did not affect the color of peeled prickly pears; however, in general, the resistance to penetration was lower in prickly pears stored in passive and active atmospheres than in unpacked fruit. The phenolic compounds content increased throughout the storage and was in accordance with the increase of antioxidant activity; beyond 20 d of storage the antioxidant activity decreased. The microbial load was favored by the modified atmosphere packaging; however, the microbial growth was delayed in fruit stored at low temperature. Judges detected the change in color in unpeeled unpacked prickly pears stored at 10°C. Low resistance to compression was observed in prickly pears stored at 4°C in an active atmosphere. The color of unpeeled prickly pear significantly affected other sensory parameters, external color was decisive for consumer acceptance of prickly pears.
The full study is available online (since September 2015) at:
http://www.sciencedirect.com/science/article/pii/S0925521415301332
Source: Carlos Enrique Ochoa-Velasco, José Ángel Guerrero-Beltrán, 'The effects of modified atmospheres on prickly pear (Opuntia albicarpa) stored at different temperatures', January 2016, Postharvest Biology and Technology, Vol. 111, pages 314–321.
Contacts:
José Ángel Guerrero-Beltrán
Departamento de Ingeniería Química, Alimentos y Ambiental
Universidad de las Américas Puebla
Sta. Catarina Mártir, Cholula,
72820, Puebla, México
Email: angel.guerrero@udlap.mx